Fix TS freezing the editor

[pascalkuthe]

Fixes #6697
Closes #338

This PR addresses TS syntax highlighting freezing the UI loop in two separate ways:

• It uses the parser timeout mechanism in TS to limit all TS parsing to 500ms. If parsing exceeds 500ms, its canceled and TS is automatically disabled for that buffer. This is preferable to a fixed size limit (as suggested in Disabling tree-sitter on big files #338) as it takes different CPU speeds/grammar speeds into account (and future optimizations in the parser/TS). If parsing takes longer than 500ms the editor always feels laggy.
• In the picker syntax highlighting is now performed in a background thread to avoid micro stutters in the UI (if trying to move after a short a delay)

[archseer]

• This is preferable to a fixed size limit

I still think there should be an upper bound but we can set it to something really high (200~500MB?)

[alexmo1997]

Is there any way to disable this?
I have some json files I would like to go through with helix (for which syntax highlighting would be great), and I'm fine with waiting a few seconds when opening them.